05.17 D60026e6 Valid since standard implementation Rev. 03, subject to change

Skype Measurement Setup for Custom Processing Tests

Data Sheet

Skype (Code 60026)Skype for Business Audio Test Specification

OVERVIEWSpeech quality assessment of VoIP sys-

tems and components is a challenge due to the various kinds of signal processing involved (e.g. echo cancellers, non-linear processors, speech codecs, VAD/voice activity detection, jitter buffer, PLC/packet loss concealment). All these aspects have a significant influence on conversational speech quality.

Since corresponding signal processing methods are used in SkypeTM for Business (formerly Microsoft® Lync®) systems, the “Skype for Business Audio Test Specifica-tion” has been developed. It defines the audio requirements for corresponding SkypeTM for Business devices and acces-sories, emphasizing those audio require-ments that significantly impact the end user experience, such as speech quality, signal noise, echo/delays, and so forth.

DESCRIPTIONThe measurement standard “Skype” is an

implementation of the “Skype for Business Audio Test Specification” for the commu-nication analysis system ACQUA by HEAD acoustics. The standard comprises tests for SkypeTM for Business devices and accesso-ries such as headsets, handsets, personal handheld and hands-free speakerphones as well as conferencing devices.

The audio quality requirements of the standard are implemented as test suites according to “Skype for Business Audio Test Specification” Chapter 4.

The measurement standard contains three different test suites which are applied depending on the device under test (DUT):

• “Skype for Business Audio Test Speci-fication for devices using all Skype for Business audio pre-processing”: this test suite is applied if the DUT is using the built-in signal processing of SkypeTM for Business (software signal processing).

• “Skype for Business Audio Test Specifica-tion for devices using custom software or hardware audio pre-processing”: this test suite is applied if the DUT is a personal

device that has its own signal processing (hardware / software signal processing).

• “Skype for Business Audio Test Speci-fication for conferencing devices”: this test suite is applied if the DUT is a USB speakerphone, room system etc., intend-ed for usage distances exceeding 0.7m mouth to microphone.

The tests implemented in the standard cover important conversational speech quality aspects such as delay measure-ments in sending and receiving direction, echo tests, speech quality in presence of background noise and during double talk.

For this purpose, the analysis methods 3QUEST, EQUEST, POLQA as well as Speech-based Double Talk and Echo Anal-ysis (according to 3GPP TS 26.131/132) are used in the “Skype” standard.

APPLICATIONS• Automated analysis of handsets,

headsets, speakerphones and other ac-cessories used for SkypeTM for Business

• Compliance testing according to “Skype for Business Audio Test Speci-fication”

SYSTEM REQUIREMENTSGeneral requirements for all DUTs and test cases:• ACQUA (Code 6810 etc.), Ad-

vanced Communication Quality Analy-sis System. Note: existing customers need a valid software maintenance agreement (SMA)

• 1 PC for ACQUA (as specified by cor-responding data sheets)

• 1 PC for Reference Client (Windows®)• ACOPT 29 (Code 6856), Option

EQUEST• ACOPT 30 (Code 6857), Option

POLQA• MFE VI.1 (Code 6462), analog USB

front end with level adjustment and integrated power amplifier with option

MFE VI-BEQ (Code 6461), binaural equalization for MFE VI.1

• One of the following soundboards: DSB II (Code 2406) or DSB III (Code 2407) or DSB IV (Code 2408)

• 2 x CXX II.3 (Code 5177-3), Cable AES/EBU XLR male 3-pin <> XLR fe-male 3-pin, 2.95 m

• Webcam for reference PC (not pro-vided by HEAD acoustics)

Specific requirements depending on DUT and test case:• cf. table on next page

Database Revision

Based on Specification Version

Min. ACQUA Version

3 V 3.0, December 2016 3.5.100(with Update 1)

Overview of database revision and specification version

05.17 D60026e6 Valid since standard implementation Rev. 03, subject to change

INFORMATION ON PSMM SKYPE (CODE 6595)

With PSMM Skype the user can exactly adjust the free field microphone and artificial mouth to the device under test with the help of a laser pointer (delivered with option PSMM Skype). Measurement positions for -7.5, 0 and 15 degree at 30, 50 and 100 cm can be set according to “Skype for Business Audio Test Specifica-tion” section 5.

Microphone and artificial mouth are not included in PSMM Skype (Code 6595).

represented by

OPTIONS• cf. table on the left

MEASUREMENTS

• cf. table on the left

DELIVERY ITEMS• Skype (Code 60026), as ACQUA

database• SkypeTM for Business installation• SkypeTM for Business Ref/DUT

editor• Documentation as PDF

• Skype Test Suite Manual• Skype for Business Audio Test Speci-

fication• V2C File (for ACQUA)• 2 Dongles (for Skype for Business

Ref/DUT editor)

Legal Notes / Notes on Trademarks: SkypeTM for Business and Windows® are trademarks of the Microsoft Corporation.© 2017 HEAD acoustics GmbH. All rights reserved.

Custom 

Handset/Headset

Custom 

Speakerphone

Custom Conferencing 

Devices

Skype for Business 

Handset/Headset

Skype for Business 

Speakerphone

SMDs (Single Measurement Descriptors)Delay SND, RCV SND, RCV SND, RCV SND, RCV SND, RCVTotal Quality Loss SND, RCV SND, RCV SND, RCV SND, RCV SND, RCVFrequency Response SND, RCV SND, RCV SND, RCV SND, RCV SND, RCVSignal Level (loud speech) SND, RCV SND, RCV SND, RCV SND, RCV SND, RCVSignal Level (normal speech) SND, RCV SND, RCV SND, RCV SND, RCV SND, RCVSignal Level (quiet speech) SND, RCV SND, RCV SND, RCV SND, RCV SND, RCVSingle Frequency Interference SND, RCV SND, RCV SND, RCV SND, RCV SND, RCVIdle channel SNR SND, RCV SND, RCV SND, RCV SND, RCV SND, RCVActive channel SpNR SND SND SND SND SNDEQUEST (Echo MOS) nominal volume ● ● ● ● ●EQUEST (Echo MOS) maximum volume ● ● ● ● ●Distortion and Noise SND, RCV SND, RCV SND, RCV SND, RCV SND, RCVTCLw ● ● ● ● ●Speech‐based Double Talk (TS 26.131/132) ● ● ● n/a n/a3QUEST S‐/N‐/G‐MOS (various background noise types)

● ● ● n/a n/a

Maximum Output Level RCV RCV RCV RCV RCVFrequency Response, different angles n/a SND, RCV SND, RCV n/a SND, RCVSidetone Masking Rate ● n/a n/a ● n/aOpen office headset distractor attenuation ● n/a n/a n/a n/aEQUEST in reverberant room with 2 near end talkers

n/a n/a ● n/a n/a

Speech‐based double talk in reverberant room with 2 near end talkers

n/a n/a ● n/a n/a

HMS II.3‐33 (Code 1230.1) ● n/a ● ● n/aHIS L (Code 1231) ●1 n/a n/a ●1 n/aHHP IV (Code 1406) or HHP III.1 (Code 1403)  ●2 n/a n/a ●2 n/aHMT III (Code 1961) ● n/a ● ● n/aHAE‐BGN (Code 6971) with necessary components, installed on separate PC

● ● ● n/a n/a

ACOPT 21 3QUEST (Code 6844) ● ● ● n/a n/aACOPT 32 Speech‐based Double Talk (Code 6859)

● ● ● ●4 ●4

Free‐field microhone n/a ● ● n/a ●Artificial mouth acc. to ITU‐T P.51 ●3 ● ● n/a ●External power amplifier for artificial mouth (not provided by HEAD acoustics) ●3 n/a ● n/a n/a

ACOPT 02 Signal Analysis (Code 6812) ● ● ● ● ●ACOPT 33 Turntable Support (Code 6844), cable CUD I (Code 6086), compatible turntable

n/a n/a n/a n/a ●

PSMM Skype (Code 6595) ●3 ● ● n/a ●

4 only needed for useful measurements, not required by the specification

3 only required for conducting the optional "Open Office Headset" tests

SMDs (Single Measurement Descriptors)

Test‐specific Requirements (in Addition to General Requirements)

Options

1 only required if DUT is a binaural headset2 only required if DUT is a handset